R-Value question. (Basement)

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R-Value question. (Basement)

I would use ROXUL in the basement,2 by 4 construct would give you R-25 (10 from the XPS,and 15 from the ROXUL),seems like overkill unless you live in like Nome or something.
How about putting a vapor retarder on the walls (Drylock or the like) framing within a half inch of the walls (but not touching),then stuff the cavities with ROXUL.
XPS is a great vapor barrier,but its pretty expensive.

R-Value question. (Basement)

Quote:

Originally Posted by spring3100

I would use ROXUL in the basement,2 by 4 construct would give you R-25 (10 from the XPS,and 15 from the ROXUL),seems like overkill unless you live in like Nome or something.
How about putting a vapor retarder on the walls (Drylock or the like) framing within a half inch of the walls (but not touching),then stuff the cavities with ROXUL.
XPS is a great vapor barrier,but its pretty expensive.

R-Value question. (Basement)

1 good thing about ' drylok ' type mtls is that you can color them by buying pigment from sher-wms,,, 1 more is that when they fail its easy to see the damage ooops, guess that's 2 its always easier doing moisture test BEFORE starting to spend $ & invest labor

R-Value question. (Basement)

Quote:

Originally Posted by ryanmcl

I have been reading that 1" foam is not sufficient to act as a vapor barrier. It must be 2" minimum. Is that an accurate statement?

Somewhere in one of the many links that GBR provides from Building Sciences (in the Insulation section) there is a statement that you can get by with 1" if the humidity levels stay low enough in the summertime). I can not provide that for you now, but do a little more searching in that section and see what you find.

R-Value question. (Basement)

I think I answered your R-10 already.... R-11 is not in the Codes for continuous insulation for a basement, your inspector is wrong; Chicago, IL; http://www.reedconstructiondata.com/...odes/illinois/ SO, IECC 2009 is your state-wide code with no local amendments...from that link.

Under that code, 10/13 is required in a basement;

"c. "15/19" means R-15 continuous insulated sheathing on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. "15/19" shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulated sheathing on the interior or exterior of the home. "10/13" means R-10 continuous insulated sheathing on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall." From; http://publicecodes.cyberregs.com/ic...9_4_par004.htm

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